Method and apparatus for manufacturing gallium nitride based single crystal substrate

Abstract

A method and apparatus for manufacturing a nitride based single crystal substrate. The method includes placing a preliminary substrate on a susceptor installed in a reaction chamber; growing a nitride single crystal layer on the preliminary substrate; and irradiating a laser beam to separate the nitride single crystal layer from the preliminary substrate under the condition that the preliminary substrate is placed in the reaction chamber.

1 . A method for manufacturing a nitride based single crystal substrate comprising: 
 placing a preliminary substrate on a susceptor installed in a reaction chamber;    growing a nitride single crystal layer on the preliminary substrate; and    irradiating a laser beam to separate the nitride single crystal layer from the preliminary substrate under the condition that the preliminary substrate is placed in the reaction chamber.    
   
   
       2 . The method as set forth in  claim 1 , wherein the irradiation of the laser beam is performed at a temperature in the range of 800˜1,200° C.  
   
   
       3 . The method as set forth in  claim 2 , wherein the irradiation of the laser beam is performed at the same temperature as a temperature at which the nitride single crystal layer is grown.  
   
   
       4 . The method as set forth in  claim 1 , wherein the nitride single crystal layer is a single crystal layer satisfying the composition of Al x In y Ga 1-x-y N (Here, 0≦x≦1, 0≦y≦1, and 0≦x+y≦1).  
   
   
       5 . The method as set forth in  claim 1 , wherein the preliminary substrate is made of one selected from the group consisting of sapphire, SiC, Si, MgAl 2 O 4 , MgO, LiAlO 2 , and LiGaO 2 .  
   
   
       6 . The method as set forth in  claim 1 , further comprising growing a low-temperature buffer layer satisfying the composition of Al x In y Ga 1-x-y N (Here, 0≦x≦1, 0≦y≦1, and 0≦x+y≦1) on the preliminary substrate before the growth of the nitride single crystal layer, 
 wherein the preliminary substrate is a silicon substrate.    
   
   
       7 . The method as set forth in  claim 1 , wherein a transparent window for irradiating the laser beam onto the preliminary substrate placed on the susceptor is formed through an upper surface of the reaction chamber.  
   
   
       8 . The method as set forth in  claim 7 , wherein: 
 the preliminary substrate is made of a material having an energy band gap wider than that of the nitride single crystal layer; and    the irradiation of the laser beam includes:    moving the preliminary substrate so that the laser beam is irradiated onto a lower surface of the preliminary substrate on which the nitride single crystal layer is formed; and    irradiating the laser beam onto the lower surface of the preliminary substrate.    
   
   
       9 . The method as set forth in  claim 1 , wherein: 
 the preliminary substrate is made of a material having an energy band gap narrower than that of the nitride single crystal layer; and    the irradiation of the laser beam includes irradiating the laser beam onto the nitride single crystal layer formed on an upper surface of the preliminary substrate.    
   
   
       10 . The method as set forth in  claim 1 , wherein: 
 the growth of the nitride single crystal layer includes: 
 first growing a nitride single crystal film having a designated thickness; and  
 secondarily growing a nitride single crystal on the first-grown the nitride single crystal film; and  
   the irradiation of the laser beam is performed between the first growth and the second growth.    
   
   
       11 . The method as set forth in  claim 1 , wherein the growth of the nitride single crystal layer includes: 
 first growing a nitride single crystal film having a designated thickness; and    secondarily growing a nitride single crystal on the first-grown the nitride single crystal film,    further comprising irradiating the laser beam between the first growth and the second growth for partially separating the nitride single crystal layer from the preliminary substrate.    
   
   
       12 . The method as set forth in  claim 11 , wherein: 
 the preliminary substrate is a silicon substrate; and    the thickness of the first-grown nitride single crystal film is 0.1˜μm.    
   
   
       13 . The method as set forth in  claim 11 , wherein: 
 the preliminary substrate is a sapphire substrate; and    the thickness of the first-grown nitride single crystal film is 5˜100 μm.    
   
   
       14 . The method as set forth in  claim 11 , wherein, in the irradiation of the laser beam for partially separating the nitride single crystal layer from the preliminary substrate, the laser beam is irradiated such that laser beam irradiation regions are separated from each other by a designated interval.  
   
   
       15 . The method as set forth in  claim 1 , wherein the growth of the nitride single crystal layer is performed by hydride vapor phase epitaxy (HVPE), metal organic chemical vapor deposition (MOCVD), or molecular beam epitaxy (MBE).  
   
   
       16 . An apparatus for manufacturing a nitride single crystal layer comprising: 
 a reaction chamber for growing a nitride single crystal therein;    a susceptor installed in the reaction chamber for fixing a preliminary substrate; and    a transparent window formed through an upper surface of the reaction chamber for irradiating a laser beam onto an upper surface of the preliminary substrate fixed to the susceptor.    
   
   
       17 . The apparatus as set forth in  claim 16 , further comprising a substrate position adjusting arm for moving the preliminary substrate so that the laser beam is irradiated onto a lower surface of the preliminary substrate fixed to the susceptor.